From Observations of Supernova Explosions in Distant Galaxies,it Is Predicted

question 388

Multiple Choice

From observations of supernova explosions in distant galaxies,it is predicted that there should be about five supernovae per century in our Galaxy,whereas we have seen only about one every 300 years from Earth.Explain.

• A) The majority of supernovae produce no visible light, only radio and X-ray radiation, which we have been able to observe from Earth for only the past three decades.
• B) Most supernovae occur in the galactic plane, where interstellar dust has hidden them from our view from Earth.
• C) Most supernovae occur in the Milky Way and can be seen only from the southern hemisphere, where there have been very few observers until recently.
• D) The majority of stars in the Galaxy are old, well beyond the supernova stage of evolution.